Abstract: A more precise algorithm(WA-C) in calculating orbital equation is given,on the base of classical Adams-Cowell algorithm.WA-C is revised by using extrapolation technology to(improve) precision.An example is tested through A-C,KSG,ACm and WA-C algorithm,and(comparison) is given.The test result shows that WA-C algorithm is more efficient to improve(precision) in orbital equation calculation then other methods.